Variable-speed gearing for bicycles.



Nu. 68|,7|8. Patented Sept. 3, 190|. G. T. MARTIN.

VARIABLE SPEED GEABING F03 BICYCLES.

(Application tiled May S1, 1801.)

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@Mmrneys Nu. BBIJIS. Patented Sept. 3, |90l.

,6. T. MARTIN. 4 vAmAsLe man Gamme Fon lcvcLes.

(Application tiled May 8l. 1901.) (No Model.)

7,7% lnvemor @Attorneys fn: Raums PETERS co.. walimex. wAsumuTuN. n. c,

UNrrnD STATES PATENT Chinon..

eri-ionen TnoMAs MARTIN, on sMITus FALLs, CANADA.

VARIABLE-SPEED GEARING FORV BICYCLES.

SPECIFICATION forming part of Letters Patent No. 681,718, dated September 3, l1901.

Application tiled May 31, 1901. Serial No. 62,515. (No model.)

To all whom, t may concern:

Be it known that I, GEORG-E THoMAs MAR- TIN, a subject of the King of Great Britain, residing at Smiths Falls, county of Lanark, Province of Ontario, Canada, have invented Y certain new and useful Improvements in VariableSpeed Gearing forBicycles; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in variable-speed gearing for bicycles and other machinery; and the primary object of the invention is the production of a compact, simple, strong, and eflicient mechanism capable of easy operation when it is desired by the rider to change from a high speed to a low speed, as when the road changes from a level to an upgrade or hill, while at other times the speed of the gearing can in like manner be changed from a low speed te a-high speedin the event of ihe rider'desiring'to spurt or travel rapidly over a level stretch of a road.

Further objects and advantages of the invention will appear in the course of the subjoined description, and the novelty vin the combination, construction, and arrangement of parts will be dened by the claims. *Y

In the drawings hereto annexed, forming a part of this specification, Figure 1 is an end elevation with a part of the crank-hanger and the casing broken away and showing portions of a changeable-speed gearing embodying my improvements. Fig. 2 is a vertical transverse sectional eleyationtaken in the plane of the dottedglinef2 2 on Fig. 3. Fig. 3 is a sectional'elevation with a part of the casing broken away and looking in a direction at right angles to Fig. 2, the plane of said section being indicated by the dotted line 3 3 on Fig. 1. Fig. 4: is a sectional plan View taken in the horizontal plane of the pedal-shaft and representing another embodiment -of my changeable speed gearing, which is especially adapted to the bevel-gearing commonly employed in chainless bicycles.

The same numerals of reference denote corresponding parts in the several iigures ol` the drawings.

5 designates the crank-hanger, which is joined or connected in any of the approved ways with the seat-post tube 5and the inclined front reach 7b of the ordinary bicycleL frame. The end portions of this crankhanger are widened or expanded, as indicated at 6 6% and these expanded portions are formed with the integral plates 7 7, and, furthermore, these plates terminate in the annular rims 8 8, all as more clearly shown by Figs. 2 and 4. The expanded or widened ends G 6 -and the rims 8 Sa of the crankhanger are interiorly screw-threaded, as iudicated at 9 10, respectively.

11 12 designate the removable face-plates, each of which is provided with an inwardlyextending flange 13, which is formed with an external or male screw-thread, and these faceplates 11 12 have the threaded flanges 13 thereof screwed into the female threaded p0rtions 10 ofthe rims 8 on the crank-hanger, whereby the face-plates are removably and xedly attached to the crank-hanger, and they serve to close the expanded end portions of said hanger in such a way that provision is made for the accommodation of the driving element and the primary gear member of a train of multiplying-gearing, all as will hereinafter more fully appear.

14 designates the pedal-shaft, which is supported by ball-bearings in the opposite faceplat`es 1l 12K As is usual in the art, the pedalshaft is externally threaded, as at 14a, in order to receive the bearing-cones 15, which are held against turning by the check-nuts 16, said cones having operative relation to the series of bearing-balls 17, which are confined in the cups 18, the latter being screwed into the central portions of said face-plates 11 12. The described construction is the preferred embodiment of the ball-bearings for the pedal-shaft, but of course any equivalent bearing may be adopted.

2O designates a hollow or tubular mandrel, the same loosely surrounding the pedal-shaft and supported within the crank-hanger by ball-bearings, so that said hollow mandrel is entirely independent of the pedal-shaft and its supporting devices. This hollow mandrel 20 is somewhat shorter than the pedal-shaft, so that the mandrel will be housed or contained entirely within the chamber formed by the crank-hanger and the face-plate there- IOO of, and with this hollow mandrel is associated the driving element for the bicycle propulsion, the same being represented by Fig. 2 in the form of a sprocket-wheel 21 when the improved variable-speed gear is used on bicycles having sprocket-chain-and-wheel gearing as the propulsion devices. As will be evident by an inspection of Fig. 4, however, this driving element 2l is in the form of a bevel-gear 22 when the improved variablespeed gearing is used as a means for driving chainless bicycles and 'kindred machinery. The sprocket-wheel 2l, forming the driving element for the chain of the propulsion mechanism, has its toothed rim disposed in the space inclosed by the integral plate 7a and the face-plate l2 at the right-hand portion of the crank-hanger, and this toothed rim is secured by bolts 2lL to the inner wheel-section 2lb, the latter being made fast with the hol- -low mandrel 2O at the right-hand end thereof.

To the end portions ofthe hollowfmandrel 2O are secured the bearing-cones 23, disposed in operative relation to the series of bearingballs 24, that are confined in the cups 25, the

. latter being screwed into the threaded portimes.

tions 9 of the widened or expanded ends 6 6a of the crank-hanger. (See Fig. 2.) It is evident that the hollow lmandrel is thus -monnted in the crank-hangerso-as to turn freely therein, and that it is independent of the pedal-shaft, which it serves to partly-inclose orhouse. This hollow mandrel greatly exceeds Ithe diameter of the pedal-shaft in order that the two clutch-sections, to be hereinafter described, may be properly fitted within the hollow mandrel and around the Ypedal-shaft.

-in the space formed by the integral plate 7 and the face-plate 1-1 at the left-hand end of the crank-hanger, and this primary member is in the form of a dished bevel-gear having oblique gear-teeth *26a and an integralhub 27, y.the latter being secured firmly to the pedalshaft 14 and extending into the left-hand end of the hollow mandrel 20', whereby said primary gear member vis made fast with the pedal-shaft, so as to rotate therewith at all The crank-hanger is provided at its .top portion with an integral enlargement forming a bearing-lug 2S for the right-hand portion of an inclined arbor or spindle 30, the left-hand portion of which arbor is supported in a bearing-lug 29, secured to the corresponding portion of the crank-hanger and in a plane above the lug 28, whereby provision is Amade on the crank-hanger for supporting the arbor or spindle at an angle to the axis of the pedal-shaft 14. Loosel)7 fitted on the arbor or spindle, so as to partake of the inclination thereof, is a sleeve or bushing 31, the length of which is equal to the space between the lugs seigle 28 29, whereby the sleeve is loosely mounted on the arbor, and it is held against endwise displacement by the lugs. The ends of said sleeve are exteriorly screw-threaded for the reception of the bearing-cones 32 and their check-nuts 33, and these cones are in coperative relation to the bearings-balls 34, the latter being confined in the cups 35. A hollow shaft 36 is provided with expandedl ends 37, the same being interiorly and externally screw-threaded. The cups 35 are threaded into the female threaded portions of the expanded ends, as shown by Fig. 2, so as to support the end portions of the hollow shaft 36 loosely upon the bushing or sleeve, that in turn is held in place by the arbor or spindle 30. It will be noted that the hollow shaft 3G surrounds and is concentric with `the sleeve and the spindle, and, furthermore, that the hollow shaft partakes of the inclination of said sleeve and the spindle, thus making provision for accommodation of the gear-pinions 38 39, which are of different sizes. The gearpinion 38 is screwed to the male thread Vlefthand end 37 of the hollow shaft, and said gear-pinion is arranged to have intermeshing engagement with the primary gear member 26 of the train of gears. The other gear 39 is screwed to the male threaded right-hand end 37 of the hollow shaft, so that it will rotate with the shaft when the latter is driven from vthe pedal-shaft 14 by the agency of the primary gear member 26 and the intermediate gear 38 of the train of gears. The gear 38 and a part of its bearing is arranged to project through a slot or opening 40, which is provided in the left-hand integral plate 7 of the crank-hanger, and another slot or opening 41 is provided in the crank-hanger proper at a point which permits the right-hand gearpinion 39 to projectvthrough the crank-hanger in order that said gear 39 may have intermeshing engagement with a shiftable gear 42, the latter constituting the final member of the train of multiplying-gears. The hollow shaft 36 and the gears 38 39 thereon are protected from dust and dirt by an inclosing casing 43, which is secured to the upper portion of the expanded ends of the crank-hanger.

The hollow mandrel 2O is provided with a series of longitudinal slots 44, preferably three in number, and said mandrel is furthermore provided with a like series of keys 45, the same extendinglongitudinally of the mandrel in parallel relation to the slots and alternating with said slots, as will be seen by reference to Fig. 3.

The hub 46 of the shiftable'gear 42, which forms the final member of the train of reducing-gearing, is snugly fitted upon the hollow mandrel, so that it is capable of a slidable movement thereon, and the inner face of this gear hub 46 is provided with the grooves in which are seated the series of longitudinal keys 45, whereby the shiftable gear 42 is made fast with the hollow mandrel, so

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that it will turn at all times therewith and yet is capable of the slidable adjustment on said mandrel. The rigid slidable connection between the shiftable gear 42 and the hollow mandrel is supplemented by the employment of the series of bolts 47, the same having their heads seated ush with the gear hub and passing through the slots 44 of the hollow mandrel, as shown by Figs. 2 and 3, thus making provision for the bolts sliding in the slots when the shiftable gear is adjusted on the hollow mandrel. These bolts serve, furthermore, as the means for operatively connectin g the shiftable clutch member 48 to the shiftable gear 42, said clutch member being arranged within the crank-hanger so as to loosely surround the pedal-shaft 14.

It is to be observed that the gear 42 and the clutch member 48 are disposed outside 0f and within the hollow mandrel, respectively; but the bolts 47 serve to unite the clutch member and the gear together in a manner toinsure simultaneous movement of the parts. This clutch member 48 has its working face 49 disposed in opposing relation to a similar working face 51 on the fast clutch member 50, the latter being made fast with the pedalshaft, near the left -hand end thereof, and adapted to turn with said pedal-shaft at all times. Furthermore, the fast clutch member 50 lies within the hollow mandrel 20 in the path of the working face on the slidable clutch member, and, if desired, this fast clutch member 50 may be formed on the hub 27 of the primary member 26 of the multiplying-gear.

Any suitable means may be provided for giving the slidable adjustment to the gear 42 and the clutch member 48,associated therewith, and as one means for giving the described adjustment to these parts I have shown the mechanism as equipped with a rocking fork or yoke 52, the latterbeing movable with a rock-shaft 53, journaled in appropriate bearings 54 at the lower portion of the crank-hanger, as shown more particularly by Fig. 3. This fork or yoke is arranged to straddle or loosely embrace the under side of the hub 46, forming a part of the shiftable gear 42, and the end portions of this yoke or fork have the pins' 55, on which are loosely supported the friction-rolls 5G, that are fitted loosely in an annular groove 57, which is provided in the hub 46 of the shiftable gear, thus making provision for the operative connection of the fork or yoke with the gear at all times. The rock-shaft 53 is provided at one end witha crank-arm 58,to which is connected a shipping-rod 59, the latter adapted to be op' erated by any suitable appliance on the bicycle and located within convenient reach of the rider. Under ordinary conditions of service the gear 42 (to the hub of which is fixed the clutch member 48 by the stub-screws 47) is in mesh with one of the intermediate members 39, which form a complete train of gearing. Under these conditions of adjustment the motion of the pedal'shaft is transmitted through the gear train 26 38 39, which causes the sprocket-wheel 21 21? to revolve with a greater speed than the pedal-shaft 14. The highspeed elements of the bicycle are thus adapted for service in order to propel the machine under the highest speed attainable by the usel of the invention on level or other favorable surfaces. When the rider desires to ascend a hill and bring into service the lower speed, it is only necessary to manipulate the said device, which moves the rod 59 and the rockshaft 53, so as to change the position of the yoke or fork 52. This change in position of the fork moves the gear 42 from intermesh with the gear 39 and by continuing the same movement of the rod 59 carries the clutch member 48 into mesh with the clutch member 50, which clutches are securely locked together by the toothed portions 51 and 49, and thereby the pedal-shaft 14 and the hollow mandrel 2O revolve as one, and consequently at a reduced speed. The train of gears 26 38 39 42, though still revolving, are disconnected at 39 and 42, and therefore are not doing any work as a propelling medium. By my invention it is possible to obtain a high or low speed, as required, and the said speed can be varied by the relative sizes of the sprocketwheels or gear-wheels.

The embodiment of the invention represented by Fig. 4 contemplates the same elements as hereinbefore shown and described, except that for the sprocket-wheel 21 I employ the bevel-gear 22 as the driving element, said bevel-gear being made fast with the righthand end of the hollow mandrel 20. The driving element 22 has intermeshing engagement with a bevel gear-wheel 60, which is secured to the forward end of a counter-shaft 61, the latter extending loosely through one of the horizontal rear forks 62 of the machineframe in a manner familiar to those skilled in the art.

Changes within the scope of the appended claims may be made in the form and proportion of some of the parts, while their essential features are retained and the spirit of the invention is embodied. Hence I do not desire to be limited tothe precise form yof all the parts as shown, reserving the right to vary therefrom.

Having thus described myinvention, what I claim as new s- 1. In a variable-speed gear of the class described, the combination with a pedal-shaft, of a single continuous hollow mandrel supported independently of the pedal-shaft a-nd provided with a driving element, a two-part clutch having one member made fast with the pedal-shaft and its other member connected to the hollow mandrel to slide thereon and to turn therewith, a train of multiplyinggearing driven by the pedalshaft and having its final member made fast with the shiftable clutch member, and adapted, under certain conditions, to propel the hollow mandrel,

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and means for shifting the slidable clutch member and the 'Iinal member of the geartrain,fsubstantially as described.

2. In a variable-speed gearof the class described, the combination with a pedal-shaft,

f of va single continuous hollow mandrel provided with a driving element, meansvfor independently 'supporting the hollow mandrel and the ypedal-shaft in concentric relation, av

trainv of multiplying-gearing having the driving member thereof propelled by the pedalshaft and with the inal'member of said geartrain tted on the hollow mandrel, a two-party clutch having one member thereof secured fast to the pedal-shaft, and means connecting v the final member of the gear-train and the shiftable clutch member fast .with one another and also connecting the same slidably with the vhollow mandrel, substantially as described.

3. In a variable-speed gear of the class de-r scribed, the combination with a pedal-shaft, of a hollowT ymandrel provided with a driving element, ya train of multiplying-gearing havmember vfast with the pedal-shaft and a shiftable member connected with the hollow mandrel and the inal member of the train, said` shiftable clutch member and the iinal mem-y ber of the gear-train being fast one with the' other and'both having shiftable relation to 'thehollow mandrel and adapted to turn at all'times therewith, and meansfor adjusting Vthe shiftable clutch member and the shiftable gear, substantially as described.

4. lIn a variable-speed gear of theclass de scribed, the combination of a crank-hanger having ltwo independent sets of vball-bearings disposed in dierent planes, a pedal-shaft mounted in one set of ball-bearings, ahollow mandrel mounted in the other set of ballbearings independently of the pedal-shaft and provided with a driving element, a twopart clutch having one member fast with the pedal-shaft and the other member connected fast with the hollow mandrel so as to be shiftable thereon, Va train of multiplying-gearing arranged for its primary member to be fast with the pedal-shaftand for its nal member to be connected shiftably to the hollow mandrel, and means for adjusting the shiftable clutch member and the final member of the train of gearing, substantially as described.

5. yIna variable-speed gear of the class de` scribed, the combination of a crank-hanger` having the expanded end portions and the removable face-plates, a set of ball-bearings supported in the expanded end portions of.

the crank-hanger, another set of ball-bearin gs supported in said face-plates, a pedal-shaft mounted in the bearings of the face-plates, a yhollow mandrel supported by the bearings of 'the crank-hanger, a two-part clutch hav-v ing its members fast with thepedal-shaft and.

the mandrel respectively, means for shifting "semis 'one of the clutch members, and a train yof' Ymultiplyingegearing havin gthe primary member fast with the pedal-shaft and its final member fast with the hollow mandrel, substantially as described.

6. In a variable-speed gear of the class described, the combination with a pedal-shaft,

gear, said shiftable clutch member and the shiftable gear being made fast one with the other and both having shiftable relation to the hollow mandrel and adapted to turn at all timestherewith, substantially as described.

7. In a variable-speed gear of the class described, the combination with apedal-shaft, of a hollow mandrel provided with'a driving element, a primarygear member fast with thepedalshaft, a stationary spindle or arbor in inclined relation to the pedal-shaft, a bushing on said arbor, a hollow pedal-shaft snpported by ball-bearings on the bushing and provided with gears one of which meshes with the primary gear member, a shiftable gear made fast with the hollow mandrel and having intermeshing engagement with the other gear of the hollow shaft, and a two-part clutch one member of which is connected with the hollow mandrel and with the shiftable gear, substantially as described.

8. In a variable-speed gear of the class described, the combination with a pedal-shaft, of a hollow mandrel provided with the slots, a shiftable .gear keyed to the hollow mandrel and having a grooved hub, a shiftable clutch member within the hollow mandrel,bolts attached to the shiftable gear, and said clutch member arranged to travel in the slots of the hollow mandrel, a rocking yoke engaging with the hub of said shiftable gear, a fast clutch member on the pedal-shaft, a primary gear member fast with the pedal-shaft, and an independently-supported yshaft having gears arranged to mesh with the primary gear member and with the shiftable gear, substan- 1 tially as described.

9. A variable-speed gear of the class described comprising a crank-hanger provided with face-plates and with independent sets of ball-bearings and with an upper casing, a pedal-shaft journaled in one set of ball-bearings, a hollow mandrel journaled in the other set of ball-bearings and provided with a driving element, the fast and shiftable clutch members secured to the pedal-shaft and having slidable connection with the hollow mandrel respectively, a primary gear lmember on the pedal-shaft, a shiftable gear member hav- IOO IIO

ing operative connection with the hollow mzm- In witness whereof I have hereunto set my drel and. with the shiftable clutch member, hand in the presence of two witnesses. and au independeutlysupported shaft arranged Within the easing and having gears GEORGE THOMAS MARVI IN' disposed to mesh with the primerygezu mem- Witnesses:

ber and with the shiftable gear respectively, -IDA M. BREGKELS,

substantially as described. l NETTIE R. WICKWARE. 

